254 SMO (UNS S31254) 6-Moly Super Austenitic Pipes
20% Chromium, 18% Nickel, 6% Molybdenum, and 0.2% Nitrogen alloy engineered to replace titanium and nickel alloys in seawater piping.
ASTM A312 UNS S31254 (254 SMO) Seawater & Process Pipe
Starlight Tubes is a certified manufacturer and exporter of 254 SMO (UNS S31254 / EN 1.4547) 6-moly super austenitic stainless steel pipes. Developed for use in halide-containing environments such as seawater, chlorinated bleach plants, and sour oil wells, 254 SMO offers double the mechanical yield strength of standard 300-series stainless steels with vastly superior localized corrosion resistance.
Our 254 SMO pipes are manufactured in seamless and welded executions per ASTM A312, ASTM A358, and NACE MR0175. Each pipe is tested with ferric chloride pitting tests (ASTM G48 Method A), 100% radiographic examination, and hydrostatic pressure verification.
Technical Specifications
ASTM / ASME CompliantTechnical Specifications — 254 SMO (UNS S31254)
Certified chemical limits and mechanical tensile properties for ASTM A312 UNS S31254
| Grade | C (max) | Mn (max) | Si (max) | P (max) | S (max) | Cr | Ni | Mo | N | Cu |
|---|---|---|---|---|---|---|---|---|---|---|
| 254 SMO | 0.020 | 1.00 | 0.80 | 0.030 | 0.010 | 19.5-20.5 | 17.5-18.5 | 6.0-6.5 | 0.18-0.22 | 0.50-1.00 |
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Direct Mill Supply for 254 SMO 6-Moly Piping
Starlight Tubes supplies fully certified 254 SMO pipes with ASTM G48 pitting corrosion testing, NORSOK compliance, and worldwide marine shipping.
Frequently Asked Questions on 254 SMO (6-Moly) Pipes
Key engineering, tolerance, and international compliance answers from our metallurgical quality desk.
6-Moly refers to super austenitic stainless steels containing approximately 6% Molybdenum and fortified with Nitrogen, providing exceptional resistance to chloride pitting and crevice corrosion (PREN ≥ 42).
Request Project Quotation for 254 SMO (6-Moly) Pipes
Submit your required sizes, wall thicknesses, material grades, and total tonnage. Our technical sales engineers respond with complete mill pricing and lead times within 24 hours.